1. Field Of The Invention
This invention relates to surgical instrumentation and, more particularly, to a surgical retractor which includes a tissue manipulation surface having an area which is selectively variable for manipulating tissue and organs during endoscopic or laparoscopic surgical procedures.
2. Description of Related Art
Most endoscopic or laparoscopic procedures are characterized by the provision of an elongated cannula structure having a relatively thin diameter with a proximal and distal end. The distal end is passed through the surrounding tissue, such as the peritoneum, into a body cavity wherein the surgical procedure or examination is to be effected, thus providing a conduit for the insertion of surgical instrumentation. A plurality of cannula structures may be used to allow operation of a variety of instruments simultaneously during a given procedure.
In conventional surgical procedures the function of holding tissue and organs in a given location to facilitate access and viewing is typically accomplished by a retractor. This instrumentation is typically in the form of a broad paddle structure or multiple fingers attached to a handle. See, for example, U.S. Pat. No. 3,467,079 to James. This structure, however, is not usable in endoscopic procedures because the retractor is too large to be insertable through the cannula structure into the operative body cavity.
Collapsible intralumen expanders or retractors have taken the form of radial fingers which are activatable to extend relative to each other upon entering the body cavity. See, for example, U.S. Pat. No. 4,654,028 to Suma, U.S. Pat. No. 4,459,978 to Kotsanis, and U.S. Pat. No. 4,909,789 to Taguchi et al. Dilators of this type are also known in the art. See, for example, U.S. Pat. No. 1,328,624 to Graham and U.S. Pat. No. 972,983 to Arthur. In each case, once the retractive or dilatory function is completed, the fingers are compressed and withdrawn.
Other collapsible retractor instruments include collapsible fingers joined by webs of resilient material which, upon insertion into the abdominal cavity through a cannula, expand to form a retractive structure. See, for example, U.S. Pat. No. 4,190,042 to Sinnreich and U.S. Pat. No. 4,744,363 to Hasson. Another surgical retractor having an expandable frame for supporting an expandable latex sheath is described in U.S. Pat. No. 5,178,133 to Pena.
Other surgical apparatus having deployable interleaved retractor blades have been described in Soviet references. See, for example, SU 736-949 which describes an instrument having an elongated housing with a plurality of blades operative at one end by means of a manipulator at the opposed end, and SU 1360-708-A which describes an instrument having a plurality of interleaved blades which cannot be manipulated at a distance and thus is unsuited for performing endoscopic or laparoscopic procedures.
Greatly improved retractor instruments have been developed and are described in commonly assigned U.S. Pat. Nos. 5,195,505 to Josefsen, and 5,199,419 to Remiszewski et al. Both of these patents describe retractor structures which include a plurality of interleaved retractor blades mounted in a tubular housing. The blades are movable between a closed position and an open position to facilitate ease of insertion and deployment through a cannula.
Despite this wide variety of available endoscopic or laparoscopic instrumentation, there remains a need for instruments that are easily manipulable and can be deployed with one hand. There is also a need for instruments that can be selectively deployed to a multiplicity of positions between a closed position and an open position. Furthermore, there is a need for endoscopic or laparoscopic retractor that incorporate the above features.